Such a friction clutch is described in the French patent application filed on Sep. 22, 1989 under the Application No. 89 12466 and published as document no. 2652397. Its friction pads are arranged to be gripped between the pressure plate and the reaction plate of the clutch, while the support members are arranged to be fixed to a driven shaft of the clutch for rotation therewith (this driven shaft being usually the input shaft of the gearbox).
In the latter, an engagement element for giving progressive engagement, which is interposed between the two friction pads comprises a plurality of projections of resilient material, at least some of which connect the two support members together, with the said projections defining channels between them. This arrangement affords good ventilation to the projections, while the friction member or clutch plate of the clutch, comprising the support members with the friction pads and resilient engagement member, has a good progressive engagement action. Under load, it adapts well to thermal deformations of the pressure and reaction plates, so that the friction pads undergo even wear. In addition, the inertia of the friction member is not unduly increased.
The support members have a thickness which is relatively low, and contribute to the progressive engagement action of the friction member of the clutch, while enabling the friction pads to be fitted without the need to have recourse to fastening rivets. This enables the low inertia of the friction clutch to be preserved.
However, the projections referred to above consist of thin bands of material, so that it can be desirable to improve their mechanical strength, especially when the clutch is rotating at high speed so that centrifugal force is increased.